3D printed spacers for ion-exchange device

Abstract

The present disclosure is directed ion-exchange systems and devices that include composite ion-exchange membranes having 3D printed spacers on them. These 3D printed spacers can drastically reduce the total intermembrane spacing within the system/device while maintaining a reliable sealing surface around the exterior border of the membrane. By adding the spacers directly to the membrane using additive manufacturing, the amount of material used can be reduced without adversely impacting the manufacturability of the composite membrane as well as allow for complex spacer geometries that can reduce the restrictions to flow resulting in less pressure drop associated with the flow in the active area of the membranes.

The invention claimed is: 
     
       1. An ion exchange membrane comprising a plurality of 3D printed spacers adhered to a surface of the ion exchange membrane, wherein each 3D printed spacer of the plurality of 3D printed spacers has the following properties:
 a first width W 1  at a first distance L 1  from the membrane surface, 
 a second width W 2  at a second distance L 2  from the membrane surface, 
 W 1 >W 2 , and 
 L 1 >L 2 . 
 
     
     
       2. The membrane of  claim 1 , wherein each 3D printed spacer of the plurality of 3D printed spacers has the following additional properties:
 a third width W 3  at a third distance L 3  from the membrane surface, 
 W 3 >W 2 , and 
 L 3 <L 2 . 
 
     
     
       3. The membrane of  claim 1 , wherein each 3D printed spacer of the plurality of 3D printed spacers has a height of 10-1000 microns. 
     
     
       4. The membrane of  claim 3 , wherein each 3D printed spacer of the plurality of 3D printed spacers has a height of 10-250 microns. 
     
     
       5. The membrane of  claim 1 , wherein a total area of the surface of the ion exchange membrane covered by the plurality of 3D printed spacers is 1-20% of total surface area of the surface of the ion exchange membrane. 
     
     
       6. The membrane of  claim 1 , wherein a volume of the plurality of 3D printed spacers is less than a theoretical maximum volume of the plurality of 3D spacers defined by multiplying a maximum width of the spacers in a x direction by a maximum height of the spacers in a y direction and by a maximum depth of the spacers in a z direction. 
     
     
       7. The membrane of  claim 6 , wherein the volume of the plurality of 3D printed spacers is less than 95% of the theoretical maximum volume of the plurality of 3D spacers. 
     
     
       8. The membrane of  claim 1 , further comprising a second plurality of 3D printed spacers on a surface of the ion exchange membrane opposite the surface with the first plurality of 3D printed spacers. 
     
     
       9. The membrane of  claim 1 , wherein ion exchange membrane is a cation exchange membrane or an anion exchange membrane. 
     
     
       10. The membrane of  claim 1 , wherein each 3D printed spacer of the plurality of 3D printed spacers have the following additional properties:
 a first depth D 1  at a first distance LD 1  from the membrane surface, 
 a second depth D 2  at a second distance LD 2  from the membrane surface, 
 D 1 >D 2 , and 
 LD 1 >LD 2 . 
 
     
     
       11. An ion-exchange device comprising:
 a pair of electrodes comprising an anode and a cathode; 
 a first ion exchange membrane and a second ion exchange membrane between the pair of electrodes, 
 wherein at least one of the first or second ion exchange membranes comprises a plurality of 3D printed spacers adhered to a surface of the at least one of the first or second ion exchange membranes such that an intermembrane spacing between surfaces of the first and second ion exchange membranes is 10-1000 microns, and 
 wherein each 3D printed spacer of the plurality of 3D printed spacers has the following properties:
 a first width W 1  at a first distance L 1  from the membrane surface, 
 a second width W 2  at a second distance L 2  from the membrane surface, 
 W 1 >W 2 , and 
 L 1 >L 2 . 
 
 
     
     
       12. The device of  claim 11 , wherein each 3D printed spacer of the first ion exchange membrane is a cation exchange membrane and the second ion exchange membrane is an anion exchange membrane. 
     
     
       13. The device of  claim 11 , wherein each 3D printed spacer of the plurality of 3D printed spacers comprise a third width at a third distance from the surface of the at least one of the first or second ion exchange membranes, wherein the third width is greater than the second width and the third distance is less than the second distance. 
     
     
       14. The device of  claim 11 , wherein an area of the surface of the at least one of the first or second ion exchange membranes covered by the plurality of 3D printed spacers is 1-20% of total surface area of the surface of the at least one of the first or second ion exchange membranes. 
     
     
       15. The device of  claim 11 , wherein each 3D printed spacer of the plurality of 3D printed spacers has the following additional properties:
 a first depth D 1  at a first distance LD 1  from the membrane surface, 
 a second depth D 2  at a second distance LD 2  from the membrane surface, 
 D 1 >D 2 , and LD 1 >LD 2 .